Between the British and sundry maharajas, India arguably built and used more railway gauges (the standard measure for the gap between parallel rail on a track) than the rest of the world put together. Disuse and a colossal government project to convert metre-gauge lines to broad gauge have killed off most, but there are still a few places, like Rajasthan and India’s northeast, where you can find metre-gauge trains. They are considerably smaller than the big broad-gauge rigs that thunder between India’s metros but the smaller scale lends an intimacy that’s almost cost. Rajasthan has several options, but many are night trains, so the best way to experience it is the Bikaner Express from Rewari in Haryana (90 km from Delhi), which takes you through progressively drier-and more starkly beautiful-country. Camels, sand dunes, an antelope all come for free in your visual package. Gauge conversion should be complete within two years and metre-gauge trains will be limited to memories and museums, so this one’s on the last-chance –to-see list.